SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8569096bb82e849fffaa1330fca7be65c5b047eb7388d9ef60ab90dde9d09e1' 
  AND token = 'HEQtuIsFkegMrqrcftP2QaWNeBtienNtV1y8QM2rRlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}